49.Submission Details java solutions

Given an array of strings, group anagrams together.

For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], 
Return:

[
  ["ate", "eat","tea"],
  ["nat","tan"],
  ["bat"]
]

Note: All inputs will be in lower-case.

题意就是对同构词进行分类，存到list之后再返回。

public class Solution {
    public List<List<String>> groupAnagrams(String[] strs) {
        Map<String,ArrayList<String>> map = new HashMap<String,ArrayList<String>>();
        for(String str : strs){
            String tmp = sortStr(str);
            if(map.containsKey(tmp)){
                map.get(tmp).add(str);
            }else{
                ArrayList<String> list = new ArrayList<String>();
                list.add(str);
                map.put(tmp,list);
            }
        }
        List<List<String>> ans = new ArrayList<List<String>>(map.values());
        // for(List<String> a : ans){
        //     Collections.sort(a);
        // }
        return ans;
    }
    
    public String sortStr(String str){
        char[] tmp = str.toCharArray();
        Arrays.sort(tmp);
        return new String(tmp);
    }
}